Electric motor driven lawn and garden appliances are very familiar to anyone having property to maintain. Typical appliances include lawn mowers, hedge clippers, chain saws, edgers, drills, and other items. As battery technology improves, frequently these appliances are powered by self contained batteries. Further, as the various governmental agencies having environmental powers regulate the pollution emissions from small gasoline engines, this use of battery powered equipment will further increase.
While electric powered appliances are useful, the customer frequently meets with some frustration due to the fact that they inadvertently overload the motor, quickly depleting a battery and/or possibly damaging the unit. The reason for this is that there is typically no overload protection or overload indication for the appliance and, unlike a gasoline motor which will audibly slow and/or stall, an electric motor will continue to drain power as long as it is switched on. This overloading of the motor is aggravated by the fact that consumers are used to the relatively inexhaustible power available in over designed gasoline motor powered units together with the indications of overload for these gasoline motors. The consumer, however, is typically not familiar with the overload characteristics of an electric motor.
In addition to the above, the necessity of providing an easy to use, but indestructible control system that can stand up to consumer abuse typically increases the cost and complexity of such controls. This abuse includes rapid cycling of the controls, trying to operate the unit with a charger connected, trying to cut too large an acreage for a given unit, overloading a mower, and other abuses.